Water scarcity footprint of cocoa irrigation in Bahia

Abstract This study simulated the water scarcity footprint (WSF) of cocoa irrigation in municipalities considered suitable for cocoa growing in the state of Bahia, according to agro climatic zoning. Irrigation demand was calculated using the model proposed by FAO (Food and Agriculture Organization of the United Nations). Subsequently, impact on water scarcity was calculated using the product of crop irrigation demand and water scarcity characterization factors of the regionalized AWARE method for Brazil. The WSF in Bahia ranged between 0.28 and 646.5 m³ of water per kilo of cocoa produced. From the defined scale, of the 417 municipalities in Bahia suitable for growing cocoa, 59% have a 'low' footprint, 18% 'medium', 10% 'high', and 12% have a 'very high' footprint. Based on these results, it is suggested that areas with lower WSF are a priority in the expansion of cocoa to avoid a possible compromise of other essential demands of the municipalities. In addition, irrigation should avoid waste, especially in regions with high levels of water scarcity. The results show that the inclusion of the WSF in agroclimatic zoning can contribute to the process of identifying potential and critical regions for new crops and the expansion of others.摘要 本研究依据农业气候区划，对巴西巴伊亚州适宜可可种植的各市县开展可可灌溉缺水足迹（Water Scarcity Footprint, WSF）模拟研究。灌溉需水量采用联合国粮食及农业组织（Food and Agriculture Organization of the United Nations, FAO）提出的模型进行计算。随后，通过作物灌溉需水量与巴西区域化AWARE方法的缺水特征因子的乘积，计算水资源短缺影响。巴伊亚州的可可灌溉缺水足迹介于每生产1千克可可需0.28至646.5立方米水之间。在该州417个适宜可可种植的市县中，59%的足迹等级为“低”，18%为“中”，10%为“高”，12%为“极高”。基于上述结果，建议优先在缺水足迹较低的区域拓展可可种植，以避免对市县其他基本用水需求造成潜在影响。此外，灌溉应避免水资源浪费，尤其在水资源短缺程度较高的区域。研究结果表明，将缺水足迹纳入农业气候区划，有助于识别新作物种植及现有作物扩张的潜在适宜区域与关键敏感区域。